Tub suspension assemblies

ABSTRACT

Apparatus for suspending a vibratory element from a support which is relatively stationary with respect to the vibratory element. The apparatus includes a first member having first and second ends. The first end of the first member is coupled to the support and the second end of the first member depends downwardly from the first end of the first member. A second member is coupled to the vibratory element for movement relative to the first member as the vibratory element moves. A tension spring has a first end and a second end. The first end of the tension spring is coupled to the first member and the second end of the tension spring is coupled to the second member.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the Oct. 6, 2003 filing date ofU.S. Ser. No. 60/509,128, titled Tub Suspension Assemblies, assigned tothe same assignee as this application. The disclosure of U.S. Ser. No.60/509,128 is hereby incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to suspension apparatus. It is disclosed in thecontext of suspension assemblies for suspending, for example, a tubwhich rotates on an axis from a relatively stationary support frame.However, it is believed to be useful in other applications as well.

BACKGROUND OF THE INVENTION

A tub is supported by tub suspension assemblies. Material or articles tobe treated (hereinafter sometimes a payload) is placed into the tub. Thepayload can be, for example, metal parts, plastic parts, clothes, or thelike. Before, during or after loading of the payload, an agent may beintroduced into the tub. The agent can be soap and water solution,paint, other organic solvent, sand, or any number of other well knowncleaning or coating agents, or the like. After addition of the payloadand the agent, where an agent is used, the tub typically is agitated fora time. After agitation, the payload and agent (again, where an agent ispresent) are removed and separated, in any convenient order. If theagent is a liquid, typically the agent is drained from the tub,typically by timed opening and closing of a system of drain valves orthe like. In such circumstances, after drainage of the agent, the tubmay be set into rotation to “spin dry” the payload in the tub to a dampcondition as the spun out agent is drained. The payload typically isthen removed for further processing.

The tub may also be the tub of a dryer in which the payload is subjectedto drying, for example, by air provided by a fan and heated by, forexample, a gas or electric heater and circulated through the tubcontents. Tubs of this general description can be used in, for example,household washing and drying machines, industrial washing and dryingmachines, laboratory painting devices, industrial painting machines,tumbling cleaning and deburring machines, and so on.

The tub may be oriented with its axis of rotation extending vertically,horizontally, or at angles to vertical and horizontal. The tub may ormay not be provided with internal agitating ribs. In use, the payload,which again can be metal parts, plastic parts, clothes, or the like, isplaced into the tub and the agent (where one is used) is added. If thetub is provided with ribs, when the tub is set in motion, the ribsagitate the payload and agent (where one is used). The motion of the tuband its contents introduces vibrations which are coupled to componentsattached to the tub.

DISCLOSURE OF THE INVENTION

According to the invention, apparatus is provided for suspending avibratory element from a support which is relatively stationary withrespect to the vibratory element. The apparatus includes a first memberhaving first and second ends. The first end of the first member iscoupled to the support and the second end of the first member dependsdownwardly from the first end of the first member. A second member iscoupled to the vibratory element for movement relative to the firstmember as the vibratory element moves. A tension spring has a first endand a second end. The first end of the tension spring is coupled to thefirst member and the second end of the tension spring is coupled to thesecond member.

Illustratively, the first member comprises a rod including an attachmentpoint, the first end of the tension spring received at the attachmentpoint.

Further illustratively, the attachment point comprises a passagewaythrough first member, the tension spring including an end configured forengagement in the passageway.

Illustratively, the vibratory element comprises a tub for processing apayload, a drive for rotating the tub about a rotary axis of the tub,and a support upon which the tub is mounted for rotation by the drive.

Further illustratively, the support includes an opening for receivingthe second member to couple to the vibratory element for movementrelative to the first member as the vibratory element moves.

Additionally illustratively, the second member comprises a passagewayfor receiving the first member.

Illustratively, the second member includes a bearing surface.

Additionally illustratively, the bearing surface comprises a surface ofrotation of a plane curve.

Further illustratively, the bearing surface is part spherical.

Illustratively, the tension spring comprises a helical coil spring andthe second member comprises a threaded portion, the threads of which aresized to threadedly engage coils of the tension spring to couple thetension spring to the second member.

Further illustratively, the apparatus comprises a dampening elementcoupled to the first member between the second member and the second endof first member.

Illustratively, the first end of the tension spring is coupled to thefirst member between the second member and the first end of the firstmember.

Additionally illustratively, the dampening element comprises acompression spring.

Additionally or alternatively illustratively, the dampening elementcomprises damper constructed from an elastomeric material.

Illustratively, the dampening element comprises a fluid damper.

Illustratively, the support includes an opening for receiving the secondmember to couple to the vibratory element for movement relative to thefirst member as the vibratory element moves. The second member includesa first end relatively closer to the first end of the first member and asecond end relatively closer to the second end of the first member. Thesecond member further comprises a passageway for receiving the firstmember, a bearing surface, and a slot extending longitudinally of thefirst member from the second end of the second member toward the firstend of the second member and intersecting the passageway. The secondmember is sufficiently resilient that the region of the second memberincluding the slot flexes as the vibratory element moves against thebearing surface to vary the frictional engagement of the sidewall of thepassageway against the first member.

Further illustratively, the second member includes two slots opposedacross the passageway.

Additionally illustratively, the first bearing surface iscomplimentarily configured to an adjacent second bearing surface of thevibratory element.

Illustratively, the support includes an opening for receiving the secondmember to permit bearing engagement of the first and second bearingsurfaces.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may best be understood by referring to the followingdetailed description and accompanying drawings which illustrate theinvention. In the drawings:

FIGS. 1 a-d illustrate partly sectional side elevational views ofassemblies constructed according to the invention;

FIGS. 2 a-c illustrate side and end elevational views of a detail of theassembly illustrated in FIGS. 1 a-d, with the view of FIG. 2 c takengenerally along section lines 2 c-2 c of FIG. 2 a; and,

FIG. 3 illustrates a side elevational view of a detail of the assemblyillustrated in FIG. 1.

DETAILED DESCRIPTIONS OF ILLUSTRATIVE EMBODIMENTS

Referring now to FIG. 1, a tub 20 is supported by tub suspensionassemblies 22, only one of which is illustrated in each of FIGS. 1 a-d.A payload is placed into tub 20. The payload can be, for example, metalparts, plastic parts, clothes, or the like. Before, during or afterloading of the payload, an agent may be introduced into the tub 20. Theagent can be soap and water solution, paint, other organic solvents,sand, or any number of other well known cleaning or coating agents, orthe like. After addition of the payload and the agent, where an agent isused, tub 20 typically is agitated for a time. After agitation, thepayload and agent (again, where an agent is present) are removed andseparated, in any convenient order. If the agent is a liquid, typicallythe agent is drained from the tub 20, typically by timed opening andclosing of a system of drain valves or the like. In such circumstances,after drainage of the agent, tub 20 typically is set into rotation to“spin dry” the payload in the tub 20 to a damp condition as the spun outagent is drained. The payload typically is then removed for furtherprocessing.

The tub 20 may also be the tub of a dryer in which the payload issubjected to drying, for example, by air provided by a fan and heatedby, for example, a gas or electric heater and circulated through the tub20 contents.

The suspension 22 of the present invention can be used in, for example,household washing and drying machines, industrial washing and dryingmachines, laboratory painting devices, industrial painting machines,tumbling cleaning and deburring machines, and so on.

The suspension 22 of the present invention can be used in applicationsin which the tub 20 is oriented vertically, as illustrated in FIGS. 1 aand 1 d, or in which the tub is oriented horizontally, as illustrated inFIG. 1 b, or in which the tub is oriented at angles to vertical andhorizontal, as illustrated in FIG. 1 c.

The tub 20 may or may not be provided with internal agitating ribs (notshown). In use, the payload, which again can be metal parts, plasticparts, clothes, or the like, is placed into the tub 20 and the agent(where one is used) is added. If the tub 20 is provided with ribs, whenthe tub 20 is set in motion, the ribs agitate the payload and agent(where one is used). The motion of the tub 20 and its contentsintroduces vibrations to the tub 20 which are coupled to componentsattached to the tub 20. These vibrations can be dampened by using tubsuspension assemblies 22 constructed according to the present invention.

Each tub suspension assembly 22 includes a rod 26. Both ends 28, 30 ofthe rod 26 are enlarged, flattened, bent or provided with threadedfasteners or other means to mount the suspension assembly 22 and tocapture other suspension assembly 22 components on the rod 26. End 28 ofrod 26 is fastened at 31 to the machine frame. End 30 of rod 26 includesa stop 32, illustratively a washer captured by a flat or enlarged regionof rod 26, a nut threaded onto end 30 of rod 26, or the like. One end 34of a component 36 is threaded or otherwise configured to couple atension spring 38, such as a helical coil spring, to component 36.Intermediate its ends 34 and 39, component 36 is formed to include abearing surface 40, which can be shaped as a surface of rotation of aplane curve about an axis, illustratively, an axis of a passageway 42which extends centrally through component 36. Illustratively, the spring38 is a uniform diameter, helical coil spring. However, a variablediameter helical coil spring, for example, a barrel-shaped spring, anhourglass-shaped spring, or a stepped-diameter spring with varyingamounts of initial tension, could be used. Illustratively, the surface40 is part spherical.

Component 36 is sized to be received through a mounting passageway 44 ina structural member 46, typically a mounting plate, to which the tub 20and its drive mechanism 48 are mounted. Spring 38 is coupled tocomponent 36, illustratively by threading coils at one end of spring 38over threads at end 34. The rod 26 is received through the centralopening in spring 38 and the passageway 42 in component 36. Theremaining end 50 of the spring 38 is coupled to the rod 26 at a location52 intermediate the ends 28, 30 of rod 26. Illustratively, this can beaccomplished by forming a flat on rod 26, providing a hole through rod26 on the flat at location 52, and passing a hook at end 50 of spring 38through the hole.

A dampening element 54, which may be, for example, a compression spring,a damper made out of rubber, plastic or other suitable material, apneumatic damper, or a hydraulic damper, may be placed on rod 26 betweencomponent 36 and end 30. Dampening element 54 cooperates with component36 to damp vibration of the tub 20/drive mechanism 48/structural member46 assembly. Illustrative dampening elements include an elastomericcylinder 60 including a passageway for receiving rod 26. Component 36can be formed with a cylindrical depression on its underside forreceiving dampening element 54, in the nature of a piston-and-cylindertype shock absorber (illustrated in FIG. 1 d), to form an additionalcompressed air cushion for dampening vibration, or the elastomericcharacter of dampening element 54 can be relied upon to dampen thevibration.

Another illustrative dampening element is another spring 62 (illustratedin broken lines in FIG. 1 c), such as, for example, a helical coilcompression spring captured between stop 32 and a downwardly facing,somewhat frustoconically shaped spring seat 64 provided on component 36.Other types of dampening elements, such as elastomeric dampeningelements, piston-and-cylinder type shock absorbers or the like, can beused in addition to, or instead of, the spring 62.

Another illustrative dampening element is illustrated in FIGS. 1 a-c and3. Component 36 has diametrically opposed, longitudinally extendingslots 68 which extend upward from the lower end 39 of component 36 tothe region where component 36 is received in passageway 44. Theunderside of member 46 is configured in the region 70 surroundingpassageway 44 so that vibration of the components coupled to member 46is coupled through the bearing engagement of surfaces 40, 70, causingcomponent 36 to flex resiliently as promoted by slots 68. Region 70 canassume any number of shapes to promote this flexing. In FIGS. 1 a-b, forexample, region 70 is substantially part spherical with a radius ofcurvature substantially equal to that of surface 40. In FIG. 1 c, region70 is generally frustoconical in shape. Of course, numerous other shapesfor surfaces 40, 70 are also available which achieve the end of causingflexing of the lower portion of component 36 to alter the frictionalforce between the sidewall of passageway 42 and rod 26 as vibrations arecoupled to component 36.

The flexing of component 36 against rod 26 varies the frictional forceof component 36 against the surface of rod 26, damping the motion ofcomponent 36 and the tub 20/drive mechanism 48/structural member 46assembly supported on surface 40. Spring 38 keeps surfaces 40, 70substantially constantly in bearing contact so that any motion of thetub 20/drive mechanism 48/structural member 46 assembly affects theforce of the inside surface of passageway 42 against the sidewall of rod26. Component 36 illustratively is constructed from filled or unfilledacetal resin. Other materials or material combinations and fillers orfiller combinations are also useful to tailor the resiliency ofcomponent 36 and the frictional characteristics of the sidewall of itspassageway 42 to the needs of a particular application.

When the tub 20 is filled, the distance 66 becomes smaller. In case ofunbalance, distance 66 may become such that dampening element 54 bottomsout on stop 32. Dampening element 54 may be chosen from a number ofdesigns and elastomeric materials, such as illustrated in FIG. 1 d, sothat it softens any such impact.

Changing of the spring constants, the load deflection rates, and thelike, of the tub suspension assemblies 22 can be achieved in any of anumber of ways in the illustrated embodiments. Dampening element 54 canbe a specially designed compression spring 62 with one, or multiple,spring constants. The spring constants of the tension spring 38 anddampening element 54, may be judiciously chosen so that the appropriatevibration damping characteristics of the tub 20/drive mechanism48/structural member 46 assembly are achieved.

Use of tension spring 38 simplifies the design and permits a reductionin components. The use of tension spring 38 tub suspension assemblies 22permits the elimination of compressed air dampers often found in priorart assemblies. A good dynamic balance normally will require relativelylow spring rates. Such spring rates can be achieved with tension springs38. The inventive configuration also permits customization of the tubsuspension assemblies 22 to the needs of a particular application, whilerequiring an inventory of relatively few different spring constants forthe tension spring 38 and dampening element 54.

Dampening at impact of dampening element 54 against stop 32 can becontrolled, for example, by selecting a different softness of thedampening element 54.

As previously noted, dampening element 54 can be a specially designedcompression spring. Also as previously noted, when dampening element 54is working in combination with tension spring 38, the deflection rate ofthe system can be made non-linear.

1. Apparatus for suspending a vibratory element from a support which isrelatively stationary with respect to the vibratory element, theapparatus including a first member having first and second ends, thefirst end of the first member coupled to the support and the second endof the first member depending downwardly from the first end of the firstmember, a second member coupled to the vibratory element for movementrelative to the first member as the vibratory element moves, and atension spring having a first end and a second end, the first end of thetension spring coupled to the first member and the second end of thetension spring coupled to the second member.
 2. The apparatus of claim 1wherein the first member comprises a rod including an attachment point,the first end of the tension spring received at the attachment point. 3.The apparatus of claim 2 wherein the attachment point comprises apassageway through first member, the tension spring including an endconfigured for engagement in the passageway.
 4. The apparatus of claim 1wherein the vibratory element comprises a tub for processing a payload,a drive for rotating the tub about a rotary axis of the tub, and asupport upon which the tub is mounted for rotation by the drive.
 5. Theapparatus of claim 4 wherein the support includes an opening forreceiving the second member to couple to the vibratory element formovement relative to the first member as the vibratory element moves. 6.The apparatus of claim 5 wherein the second member comprises apassageway for receiving the first member.
 7. The apparatus of claim 5wherein the second member includes a bearing surface.
 8. The apparatusof claim 7 wherein the bearing surface comprises a surface of rotationof a plane curve.
 9. The apparatus of claim 8 wherein the bearingsurface is part spherical.
 10. The apparatus of claim 5 wherein thetension spring comprises a helical coil spring and the second membercomprises a threaded portion, the threads of which are sized tothreadedly engage coils of the tension spring to couple the tensionspring to the second member.
 11. The apparatus of claim 1 furthercomprising a dampening element coupled to the first member between thesecond member and the second end of first member.
 12. The apparatus ofclaim 11 wherein the first end of the tension spring is coupled to thefirst member between the second member and the first end of the firstmember.
 13. The apparatus of claim 12 wherein the dampening elementcomprises damper constructed from an elastomeric material.
 14. Theapparatus of claim 12 wherein the dampening element comprises a fluiddamper.
 15. The apparatus of claim 1 wherein the second member comprisesa dampening element for exerting a force on the first member as thevibratory element moves.
 16. The apparatus of claim 15 wherein thesupport includes an opening for receiving the second member to couple tothe vibratory element for movement relative to the first member as thevibratory element moves, the second member includes a first endrelatively closer to the first end of the first member and a second endrelatively closer to the second end of the first member, the secondmember further comprises a passageway for receiving the first member, abearing surface, and a slot extending longitudinally of the first memberfrom the second end of the second member toward the first end of thesecond member and intersecting the passageway, the second member beingresilient so that the region of the second member including the slotflexes as the vibratory element moves against the bearing surface tovary the frictional engagement of the sidewall of the passageway againstthe first member.
 17. The apparatus of claim 16 wherein the secondmember includes two slots opposed across the passageway.
 18. Theapparatus of claim 16 wherein the first bearing surface iscomplimentarily configured to an adjacent second bearing surface of thevibratory element.
 19. The apparatus of claim 18 wherein the supportincludes an opening for receiving the second member to permit bearingengagement of the first and second bearing surfaces.
 20. The apparatusof claim 16 wherein the first member comprises a rod.